Containerized shipping has significantly reduced the cost of transporting goods, by eliminating the need for separate handling at intermediate points between the initial shipping point and the final destination. The cost savings have been realized by using the process of loading goods into a standardized container and shipping the loaded container to its final destination. When it is necessary to transfer the goods from one mode of transport to another, the container is handled as a unit. Standardized containers are produced with prescribed dimensions, having square ends measuring eight feet on a side and two standard lengths of forty feet and twenty feet. The corners of standard containers are provided with corner castings having flat surfaces to facilitate stacking of the containers and a standard pattern of openings designed to receive equipment for lifting the containers and devices for locking adjacent containers together. A double stacking cone with a twist lock is a conventional device for releasably joining adjacent corner castings of stacked containers. The standard containers are known as intermodal containers, because the standard dimensions and corner castings facilitate handling each container as a unit for loading on appropriately fitted ships, appropriately fitted railroad rolling stock, and on appropriately fitted semi-trailers. The locking devices used for interlocking stacked containers also serve for locking intermodal containers in place on ships, rolling stock, and semi-trailers, which have appropriate fittings, such as corner castings, for interlocking with standard corner castings of the containers.
The semitrailer chassis, which may be pulled by a conventional tractor, is an essential element in the intermodal transportation industry. The semi-trailer chassis consists of one or more longitudinal beams connected with a transverse front bolster and with a transverse rear bolster. The front portion includes a hitch mechanism for attaching the trailer to a tractor and the rear portion includes a wheel set. The trailer includes an intermediate resting stand. The front and rear bolsters are provided with standard corner castings, on outboard ends, such that standard intermodal locks, such as the double stacking cone with twist lock, can be used to secure a standard container on the semi-trailer chassis, to provide a stable load for transportation over a highway.
It is desirable to transport semi-trailer chassis using ship, rail, and truck as means for transportation. A semi-trailer chassis designed to haul standard containers will not fit inside a standard container, so chassis being shipped must be handled as separate items of cargo or must be contained in a specialized packing system. The Maersk Company has designed a specialized packing system for semi-trailers. The Maersk system packs four chassis as a bundle and provides fittings, having standard corner castings, to allow handling of the bundle in intermodal facilities using conventional equipment. An horizontal platform supports the four chassis in a stack. Four upstanding pillars extend from the platform, the ends of the pillars define eight corners, with corner castings, matching the dimensions of a standard intermodal container. The packing system cannot be stacked and cannot be easily broken down. Chassis typically follow a one-way travel route, from a point of manufacture to a point of delivery and it is desirable to have a chassis packing system, which can be easily broken down, for return shipment inside a standard container. There is a need for an improved and stackable intermodal semi-trailer chassis packing system. There is a need for a semi-trailer chassis packing system, which may be easily broken down and re-constructed.